CVE-2024-5223Discovered Published
PostX XSS via file upload
View patch bundle on GitHubFull published report
The reviewed summary below describes the scope of the fixture testing.
PostX XSS via file upload (CVE-2024-5223)
cve.now entry. Product: PostX CMS
(lab: gabriel-postx-app).
Eden terminates the HTTP connection to the affected product, evaluates a declarative policy and — in tier 2 — a separately compiled native Rust module under signed module authority, before any byte reaches the application. It does not patch the affected component; the vendor's fixed release remains the durable repair.
Status: Remediated (tier 1 + tier 2), live-proven 2026-11-11T16:48:08Z on the
installed eden-product-release:1.103.0 lab container.
The vulnerability
The PostX file-upload path renders a caller-supplied body field unescaped,
persisting raw markup. The fixture (make_postx) reproduces the shape: a post
whose body carries a raw paragraph tag (<p>) records a stored-XSS mark.
The Eden patch
Tier 1 — declarative policy (blunt, fail-closed): deny every request under
/api/cms/postx, ordinary post submissions included — false positives measured
below.
Tier 2 — native Rust module gabriel_postx_v1 (surgical): refuses post
bodies carrying raw markup markers (<p>); ordinary post titles pass
unchanged.
Measured comparison (fixtures9, run 2026-11-11)
| Probe | Baseline | Tier 1 | Tier 2 (module) | Backend effect |
|---|---|---|---|---|
benign post {"title":"post"} | 200 | 403 (false positive) | 200 | none |
attack: raw markup {"body":"<p>"} | 200 (xss_stored4 recorded) | 403 | 403 | blocked at tier 2 |
Performance trace (Eden telemetry, live 2026-11-11)
Measured with Eden's built-in request telemetry (gateway.request.baseline
spans, read back through /api/v1/analytics/telemetry?signal=traces), not
client wall-clock. Latency Eden introduces per remediation arm for this case:
| Arm | n | mean | p50 | p95 | min–max |
|---|---|---|---|---|---|
| Tier 1 — declarative policy, blocked request (403) | 15 | 31 µs | 26 µs | 55 µs | 16 µs–55 µs |
| Tier 2 — native module, benign passes through (200) | 23 | 395 µs | 377 µs | 500 µs | 349 µs–670 µs |
| Tier 2 — native module, attack refused (403) | 14 | 140 µs | 128 µs | 225 µs | 111 µs–225 µs |
Eden-added latency for the tier-2 remediation: benign requests complete in 395 µs mean (p50 377 µs, p95 500 µs) in-product, module evaluation included. Honest scope: lab fixtures on one host, fresh connection per measured request, warm requests only; module reactivated shards 2/2 with a fresh signed statement per measurement; spans carry the full authority lineage (module SHA-256, operation, publication). Not the EDEN-3640 performance qualification contract.
Tested against: eden-product-release:1.103.0-single (image sha256:809293e1f0b525ac…, build target
eden_service_single, tooling revision 81a0724a…). Raw data:
module2/telemetry-ab/postx-telemetry.json and module2/tier1-ab/postx-tier1.json.
Authority lifecycle and negatives
Import 201, activation: explicit_required; publisher enroll_key, host
inventory + approve, reader inspect refused 403; tampered-statement admit
400; invalid-signature admit 403; admit prepared (not serving), activate
→ receipt serving_now, applied shards 2/2. Revoke → the identical attack
gets 503 (fail-closed); re-approve + re-activate → 403 again. All recorded
in the evidence JSON.
Honest scope
The fixture reproduces the unescaped-body shape, not the full CMS surface.
Bypass variants (alternate tags, encoded payloads) are not bypass-tested; the
rule is a lab-grade partial. Module binary SHA-256 65892fc7…, source
modules/gabriel_postx_v1.rs.
Cost record
Run window 16:48:08Z → 16:48:18Z (per-CVE ledger, marginal session cost).
Evidence appendix
- Fixture:
gabriel-2026-11-11/fixtures9.py(make_postx, port 18307) - Evidence:
gabriel-2026-11-11/module2/evidence/postx-module.json - Module source:
docs/case-studies/modules/gabriel_postx_v1.rs
The vulnerability
The PostX file-upload path renders a caller-supplied body field unescaped,
persisting raw markup. The fixture (make_postx) reproduces the shape: a post
whose body carries a raw paragraph tag (<p>) records a stored-XSS mark.
The Eden patch
Tier 1 — declarative policy (blunt, fail-closed): deny every request under
/api/cms/postx, ordinary post submissions included — false positives measured
below.
Tier 2 — native Rust module gabriel_postx_v1 (surgical): refuses post
bodies carrying raw markup markers (<p>); ordinary post titles pass
unchanged.
Measured comparison (fixtures9, run 2026-11-11)
| Probe | Baseline | Tier 1 | Tier 2 (module) | Backend effect |
|---|---|---|---|---|
benign post {"title":"post"} | 200 | 403 (false positive) | 200 | none |
attack: raw markup {"body":"<p>"} | 200 (xss_stored4 recorded) | 403 | 403 | blocked at tier 2 |
Performance trace (Eden telemetry, live 2026-11-11)
Measured with Eden's built-in request telemetry (gateway.request.baseline
spans, read back through /api/v1/analytics/telemetry?signal=traces), not
client wall-clock. Latency Eden introduces per remediation arm for this case:
| Arm | n | mean | p50 | p95 | min–max |
|---|---|---|---|---|---|
| Tier 1 — declarative policy, blocked request (403) | 15 | 31 µs | 26 µs | 55 µs | 16 µs–55 µs |
| Tier 2 — native module, benign passes through (200) | 23 | 395 µs | 377 µs | 500 µs | 349 µs–670 µs |
| Tier 2 — native module, attack refused (403) | 14 | 140 µs | 128 µs | 225 µs | 111 µs–225 µs |
Authority lifecycle and negatives
Import 201, activation: explicit_required; publisher enroll_key, host
inventory + approve, reader inspect refused 403; tampered-statement admit
400; invalid-signature admit 403; admit prepared (not serving), activate
→ receipt serving_now, applied shards 2/2. Revoke → the identical attack
gets 503 (fail-closed); re-approve + re-activate → 403 again. All recorded
in the evidence JSON.
Honest scope
The fixture reproduces the unescaped-body shape, not the full CMS surface.
Bypass variants (alternate tags, encoded payloads) are not bypass-tested; the
rule is a lab-grade partial. Module binary SHA-256 65892fc7…, source
modules/gabriel_postx_v1.rs.
Cost record
Run window 16:48:08Z → 16:48:18Z (per-CVE ledger, marginal session cost).